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Vacuum distillation : ウィキペディア英語版 | Vacuum distillation
Vacuum distillation is a method of distillation whereby the pressure above the liquid mixture to be distilled is reduced to less than its vapor pressure (usually less than atmospheric pressure) causing evaporation of the most volatile liquid(s) (those with the lowest boiling points). This distillation method works on the principle that boiling occurs when the vapor pressure of a liquid exceeds the ambient pressure. Vacuum distillation is used with or without heating the mixture. ==Laboratory-scale applications==
Laboratory-scale vacuum distillation is used when liquids to be distilled have high atmospheric boiling points or chemically change at temperatures near their atmospheric boiling points.〔( Distillation ) (CU Boulder Organic Chemistry Teaching Labs)〕〔(Vacuum Distillation: New Method for Analyzing Organic Chemicals in a Wide Array of Samples ) (United States Environmental Protection Agency)〕〔(What is vacuum distillation? ) (Argonne National Laboratory's NEWTON Ask-A-Scientist)〕 Temperature sensitive materials (such as beta carotene) also require vacuum distillation to remove solvents from the mixture without damaging the product. Another reason vacuum distillation is used is that compared to steam distillation there is a lower level of residue build up. This is important in commercial applications where heat transfer is produced using heat exchangers. There are many laboratory applications for vacuum distillation as well as many types of distillation set-ups and apparatuses. Safety is an important consideration when using glassware as part of the set-up. All of the glass components should be carefully examined for scratches and cracks which could result in implosions when the vacuum is applied. Wrapping as much of the glassware with tape as is practical helps to prevent dangerous scattering of glass shards in the event of an implosion.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Vacuum distillation」の詳細全文を読む
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